Add flour and salt and gradually stir in milk. Bring to boil; boil 2 minutes. Remove from heat and stir in cheese and pimento; stir until cheese is melted.
Place half in a 2-quart greased dish. Top with half of the sauce. Repeat layers.
Baked uncovered at 325 degrees for 25 minutes or until bubbly. Sprinkle with paprika. Makes 8 to 10 servings.